package com.lagou.filter;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

public class AddStudentFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        HttpSession session = request.getSession();
        Object user = session.getAttribute("user");

        if (null == user) {
            request.setAttribute("msg", "请登录。。");
            RequestDispatcher requestDispatcher = request.getRequestDispatcher("/index.jsp");
            requestDispatcher.forward(request, response);
        }
        else {
            filterChain.doFilter(servletRequest, servletResponse);
        }
    }

    @Override
    public void destroy() {

    }
}
